In an electrochemical reaction process of charging and discharging of a lithium ion battery, a molecular structure of electrode material of the lithium ion battery is not changed theoretically (i.e., the electrochemical reaction process is a topotactic reaction). However, practices prove that overdischarge of the battery often causes local collapse of the molecular structure of the lithium ion battery, and has a great influence on life of the lithium ion battery. For example, relevant standards of the lithium ion battery specify that: a cut-off discharging voltage of a single lithium ion battery is 2.5V to 2.7V. However, in actual application, a voltage of the single lithium ion battery is often lower than this voltage, causing overdischarge of the battery. The molecular structure of an electrode of the overdischarged battery may generate the local collapse. The local collapse is repairable, and needs to be repaired during charging.
An existing charging technology of the lithium ion battery follows a charging habit of a lead acid battery, i.e., a charging voltage of each phase is manually set for charging in a constant-current and constant-voltage mode. Such charging mode causes too large or too small potential gradient inside the battery, or causes unreasonable current supply capability, cannot ensure that an electrochemical reaction of battery charging is performed according to objective actual conditions of the battery, and causes too low charging efficiency. Even some processes obviously violate a rule of the electrochemical reaction, causing an influence on the service life of the battery due to damage to the battery.